1. Field of the Invention
The present invention relates to sliding mechanisms and, particularly, to a portable electronic device with two or more housings configured with a sliding mechanism such that one housing is allowed to slide with respect to another housing in a longitudinal direction.
2. Description of related art
Portable electronic devices have been increasingly widely used with a multiplicity of functions. A mobile telephone terminal is exemplified as a portable electronic device that provides wireless communication services to its subscriber while wirelessly communicating with its base station. Rapid development in the field of information and telecommunication business has made it possible for mobile users to use a variety of functions and types of mobile phones available on the market. These mobile telephone terminals are generally classified into three or more types of terminals, such as, e.g., a bar-type terminal, a flip-type terminal with a flip cover, and a foldable terminal with a folding mechanism adapted to be opened and closed about a main body at a given angle.
The bar-type terminal is generally formed with a single body housing so that various data input/output means and a receiver and transmitter set are arranged on the housing, and a keypad assembly utilized as a data input/output means is fully exposed. Thus, a bar-type terminal may suffer from error due to careless manipulation by its user, and its design requires a relatively long distance between the receiver set and the transmitter set, which may lead to serious limitations in making the terminal smaller.
The folding-type or foldable terminal generally incorporates a main body, a folding portion, and a hinge module for coupling the main body and the folding portion, so that rotation of the folding portion allows opening or closure of the folding portion with respect to the main body. The main body is provided with a data input/output means, such as, for example, a keypad and a receiver set. Thus, when the folding portion is in the closed state on the main body and the terminal is, effectively, in a standby mode, the terminal can prevent any undesired operation error or malfunction since the folding portion is adapted to fully cover the keypad. However, in a telephone mode, the folding portion is usually rotated away from the main body of the mobile phone to ensure that there is enough distance between the receiver and the transmitter of the phone. As a result of this ability to fold, the design of this type of terminal may be made much smaller, at least for storage purposes. As such, mobile users recently have preferred foldable terminals to any other type of mobile communication terminals.
When using flip-type or foldable terminals, the hinge module rotatably couples the flip member or the folding portion with the main body. The hinge module operates in such a manner that when the flip or folding portion of the mobile terminal is opened to rotate up to a specified threshold angle about the main body, a continuous acting force is generated by the hinge module and is applied in the direction of opening, without application of additional external force by a user. Meanwhile, when the flip or folding portion of the mobile terminal is rotated during closing below a specified threshold angle about the main body, a continuous acting force is generated by the hinge module and is applied in the direction of closure, without application of more force by the user.
In the meantime, as more diverse design concepts are introduced in the design of mobile communication terminals, a sliding type of mobile terminal has recently become widely used. The sliding-type design typically includes two housings in which one housing is slidably opened or closed with respect to the other housing. However, these sliding type mobile terminals do not yet offer a variety of different designs, and for this reason, its users may feel some inconvenience in that they have to manually slide one housing with respect to the other housing in order to open or close it.
What is needed, therefore, is a sliding mechanism for use in a portable electronic device (e.g., a mobile phone terminal) that can overcome the above-mentioned shortcomings.